RecruitingPHASE3INTERVENTIONAL

A Study of Zolbetuximab Together With Pembrolizumab and Chemotherapy in Adults With Gastric Cancer

This study is investigating a new medication called zolbetuximab for adults with advanced stomach cancer or cancer where the food pipe joins the stomach (GEJ cancer). These cancers must have a protein called Claudin 18.2 but not HER2. Zolbetuximab is thought to work by helping your immune system find and fight cancer cells. Researchers want to see how well it works when given with pembrolizumab (another immune-boosting drug) and chemotherapy, compared to pembrolizumab and chemotherapy alone. Participants will receive one of these combinations, with some getting a dummy drug (placebo) instead of zolbetuximab, chosen randomly. The main goal is to find out if zolbetuximab helps people live longer.

At a glance

Status

Recruiting

Phase

PHASE3

Sponsor

Astellas Pharma Global Development, Inc.

Enrolment target

500

Start

22 May 2025

Estimated completion

30 Sep 2028

Locally Advanced Unresectable Gastroesophageal Junction (GEJ) Adenocarcinoma or Cancer Locally Advanced Unresectable Gastric Adenocarcinoma or Cancer Metastatic Gastric Adenocarcinoma or Cancer Metastatic Gastroesophageal Junction (GEJ) Adenocarcinoma

What is this study about?

This study is looking into a new treatment called zolbetuximab for a type of cancer that starts in the stomach or where your food pipe (oesophagus) meets your stomach. This is called gastroesophageal junction (GEJ) cancer. This particular study is for people whose cancer has either spread to other parts of the body (metastatic) or has grown into nearby tissues and can't be removed by surgery (unresectable).

Zolbetuximab works by targeting a specific protein called Claudin 18.2, which is found on the surface of some cancer cells. When it attaches to this protein, it's thought to encourage your body's immune system to attack the cancer. The study is particularly for cancers that have Claudin 18.2 but don't have another protein called HER2. Researchers want to see if adding zolbetuximab to existing treatments – an immunotherapy drug called pembrolizumab and chemotherapy – helps people live longer compared to getting pembrolizumab and chemotherapy alone.

Taking part means you'll either receive zolbetuximab along with pembrolizumab and chemotherapy, or a 'dummy' drug (placebo) instead of zolbetuximab, but still with pembrolizumab and chemotherapy. Which group you're in is decided by chance, and neither you nor your doctors will know which treatment you're getting. This helps us understand how effective zolbetuximab truly is.

Key takeaways

This study tests a new drug, zolbetuximab, for advanced stomach/GEJ cancer.
It targets a specific protein (Claudin 18.2) on cancer cells.
You'll also receive standard immunotherapy (pembrolizumab) and chemotherapy.
Participation involves either zolbetuximab or a placebo, chosen randomly.
Regular clinic visits, health checks, and scans are part of the study.
The main goal is to see if zolbetuximab helps people live longer.

Who may be eligible?

To be considered for this study, you need to be an adult with stomach cancer or GEJ cancer that has spread or cannot be removed by surgery. Important conditions for your cancer are that it must have a protein called Claudin 18.2, but not HER2. Doctors will check a sample of your cancer to confirm this.

You also need to be well enough to take part, with a good quality of life. You can be enrolled even if you've had some standard cancer treatments before. However, the study might not be right for you if you have certain other serious health problems, such as blockages or bleeding in your gut, specific untreated cancers in your nervous system, certain heart conditions, or ongoing infections.

Quick self-check

Are you an adult aged 18 or over?
Do you have stomach or GEJ cancer that has spread or cannot be removed by surgery?
Has your cancer been tested and confirmed to have the Claudin 18.2 protein and not HER2?
Are you generally well enough to manage daily activities?
Do you not have major gut problems like blockages or bleeding?
Do you not have specific severe heart conditions or active infections?

This is a guide only — the research team will confirm whether you can take part.

What does participation involve?

If you join the study, you will receive one of the specific treatment combinations. Treatments are given in cycles lasting 6 weeks. Zolbetuximab (or the placebo) is given as a drip into a vein every 2 or 3 weeks. You'll also receive chemotherapy (either CAPOX or mFOLFOX6) and pembrolizumab. Chemotherapy involves either pills and drips, or just drips, depending on the type. Pembrolizumab is also given as a drip every 3 or 6 weeks.

You'll continue treatment until your cancer gets worse, you can't tolerate the treatment, or you need different cancer care. Pembrolizumab may be given for up to two years. Throughout the study, you'll have regular visits to the clinic for health checks, including scans to monitor your cancer and check for any side effects. After stopping treatment, you'll have follow-up visits and phone calls to continue monitoring your health and cancer progression for some time.

Potential risks and benefits

Participating in a study like this might offer the potential benefit of trying a new treatment that could improve your health outcomes. However, as with any medicine, there are potential risks, and you might experience side effects from the study drugs. The research team will closely monitor you for any medical problems. Your wellbeing is paramount, and you are free to withdraw from the study at any time, for any reason, without it affecting your usual medical care.

Locations (238)

UAB Medicine - UAB Hospital
Birmingham, United States· Recruiting
CBCC Global Research - Comprehensive Blood & Cancer Center
Bakersfield, United States· Recruiting
TOI Clinical Research
Cerritos, United States· Recruiting
The Angeles Clinic and Research Institute, West Los Angeles Office
Los Angeles, United States· Recruiting
Hartford HealthCare - Hartford Hospital
Hartford, United States· Recruiting
Yale University School of Medicine
New Haven, United States· Recruiting
Piedmont Physician Medical Oncology Atlanta
Atlanta, United States· Recruiting
Northwestern Memorial Hospital
Chicago, United States· Recruiting
Franciscan Health Oncology and Hematology Specialists
Indianapolis, United States· Recruiting
Holden Comprehensive Cancer Center
Iowa City, United States· Recruiting
University of Kansas Cancer Center
Westwood, United States· Recruiting
Saint Elizabeth Medical Center Edgewood
Edgewood, United States· Recruiting

+226 more sites — see the official record for the full list.

Common questions

What is zolbetuximab?

It's a new medicine being tested that aims to help your immune system fight stomach or GEJ cancer by targeting a specific protein on the cancer cells.

What is a placebo?

A placebo looks exactly like the study medicine (zolbetuximab) but doesn't contain any active drug. It helps researchers fairly compare the new treatment.

Why can't I know if I'm getting zolbetuximab or the placebo?

This is done to prevent bias. If doctors and patients don't know who's getting which treatment, it ensures results are as accurate and fair as possible.

How long will I be on the study treatment for?

You'll continue treatment until your cancer worsens, you can't tolerate the treatment, or you need other cancer care. Pembrolizumab can be given for up to 2 years.

What happens after I stop taking the study treatment?

You'll have follow-up clinic visits and phone calls with the study team to monitor your health and cancer progression.

How to find out more

Astellas Pharma Global Development Inc.

astellas.registration@astellas.com 800-888-7704 Official trial record

Always speak to your GP or specialist before deciding to take part in a study.